Method of regulating the blast-pressure of converters



(No Model.)

4 J. P. WITHEROW.

METHOD OF REGULATING THE BLAST PRESSURE 0F CONVERTERS.

No. 317,264. Patnte'd May 5, 188.5.

Inventor.

With/gases.

fi/M

' UNITED STATES PATENT OFFICEO JAMEs P. WITHEROW, or PITTSBURG, PENNSYLVANIA.

METHOD OF REGULATING THE BLAST-PRESSURE 0F CONVERTERS;

SPECIFICATION forming part of Letters Patent No. 317,264, dated May 5, 1885.

=, Application filed March 19, 1835. (No model.)

To all whom it may concern.-

Be it known that I, Turns 1?. WITHEROW, of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Method of Regulating the Blast-Pressure of Converters; and I do hereby declare the following to be a full, clear, and exact description thereof.

In fixed converters for treating molten metal the tuyeres are usually arranged in the sides below the metal-line, and in such case it is necessary to make provision for preventing the metal from entering the tuyeres, as it would then be liable to chill and stop up the tuyereholes, necessitating frequent renewals of the tuyeres. and valves have been used, and also a single valve arranged in the blast-main, which was used to reduce the pneumatic pressure to the degree necessary to sustain the ferrostatic pressure at the mouths of the tuyeres when the active treatment of the charge was not going on.

There are objections to each of these methods; and my improvement consists in regulating the pressure at the tuyeres mouths during the operation of the converter by varying the speed of the blast-engine, so that the pressure shall run from the high pressure required during the period of conversion or active treatment to a lower pressure, which will counterbalance the ferrostatic column in the converter and keep the tuyeres clear. By my invention I bring the blast-engine directly under the management of the blower, (the person in charge of the converter,) and thus put the entire operation under one control, insuring greater certainty in the nice operations of the converter.

The process in the converter is so rapid and the efiects produced so varying that great precision and nicety in details-such as the pressure of the blast, length of blow, &c.are of the greatest importance, and all devices and expedients whichtend thereto are of moment.

To enable others skilled in the art to make use of my invention, I will now describe it by reference to the accompanying drawing, which is a view showing the blast-engine and controlling devices in elevation and the converter in vertical section.

For this purpose tuyere stoppers The blast-engine a is of the usual construction, and communicates with the converter b by a blast-main, 0. Situate at any convenient point in the blast-main is a relief-valve, (Z, which, in case the pressure of the blast should exceed that which is desired for the converter, will open and permit the escape of a sufficient quantity of air to relieve the pressure and reduce it to the desired degree. The blast-main may be provided with a suitable valve, 6, for shutting off the blast, if desired. Mounted in suitable bearings is a shaft or spindle, f, provided with a hand-wheel, f, at the end nearest the converter b. This spindle is connected with the stem 9 of the cut-off valve of the blast-engine by means of the shafting and gearing h or other suitable power-connection devices, whereby the admission of steam to the cylinder of the engine may be controlled by the operation of the hand-wheel f. The handwheel f or other means of manipulation is arranged at or near the converter 1), so as to be under the control of the blower. In this way the management of the blast-engine and the operations of the converter are put under a single control, whereby precision and uniformity are insured and the danger of the loss and trouble from confusion of orders or misunderstanding between the managers of these two important parts of the plant are avoided. By this arrangement the services of an engineer in the engine-house may be dispensed with. By the manipulation of the hand-wheel f the blower is enabled to regulate the blast both as to volume and pressure at will, and when it is desired to stop the blow he can do it instantly by closing the valve 6. This latter operation does not necessarily involve the stopping of the engine, because as soon as the gate-valve is closed the relief-valve 01 will be opened by the pressure and permit the blast to escape into the air.

By my improvement, in which I extend the functions of necessary parts, I am enabled to do away with all valves, stoppers, and other devices for controlling the pressure of the blast at the tuyeres, and to accomplish the same result in a speedy and efficient manner by varying the speed of the blast-engine. The whole volume of the blast being directly under the control of the blower, the operations of the ICO converter are not liable to be injuriously affected by any defects which may occur in separate valves at one or'more of the tuyeres while the others are in good working order. The blast being equal at the tuyeres, they are 'not liable to get out of order or stop up, and

in my said converter is usually blown at about eight pounds blast-pressure.

The variation in the speed of the blastengine necessary in the practice of my invention with such converters is such as to give a pressure at the tuyeres of from three pounds up to or above eight pounds.

YVhat I claim as my invention, and desire to secure by Letters Patent, is-

In the pneumatic process of refining iron, the method of preventing the molten metal from entering the tuyeres when the charge is not under blow, which consists in supplying air under the usual pressure for the treatment of the charge, and when desired to hold the metal in the converter without subjecting it to the action of the blast, reducing the blastpressure to the degree necessary to counterbalance the ferrostatic column at the tuyeres, by varying the speed of the blowing-engine accordingly, substantially as described.

In testimony whereof I have hereunto set my hand this 16th day of March, A. D. 1885.

J AMES 1?. WITHEROW.

Witnesses:

WV. 13. CORWIN, THOMAS B. KERR. 

